I agree that "negative" is a misnomer for emotions: they all have a positive purpose. I use those labels "positive" and "negative" emotion for linguistic convention, but I'm letting it go more and more.
I think that thinking of "positive" emotions as ones that move you toward what you want and "negative" ones as away-from motivations is also a habitual convention of thought, outdated and outmoded.
The emotions people think of as being negative are very powerful towards-motivators: they are like brilliant, colorful flags that say, "Look here! There's something here to learn that will make a big difference!"
And while habitual convention of thought tends to have people thinking, well, I feel bad around this thing, that means I must remove it or get away from it or kill it, again I think that although that has served a positive purpose in protecting us, it's outdated and unsophisticated in the face of inauthentic threat. We have far more sophisticated resources for transforming what occurs as making us angry, sad, afraid, hurt, ashamed, or guilty so that freezing, fighting and fleeing are no longer our only options. We have all the resources we need to move from a constant emergency state to a state of Mastery.
And those "negative" emotions can support us in that.